328 DISSECTION OF THE RABBIT 



ligature round the penis half an inch from its end, to prevent 

 the air escaping. 



Clean the various structures in the order given below. 



e, The urine-genital canal, or urethra, is the continua- 



tion backwards of the neck of the bladder, through 

 the pelvic cavity. It is a straight tube, with thin 

 and very vascular walls, which lies immediately 

 dorsal to the pelvic symphysis, and ventral to the 

 rectum. Behind the symphysis it is continued 

 into the penis. 



f, The penis is an elongated body, projecting from the 



ventral surface of the animal, immediately behind 

 the pelvic symphysis and in front of the anus. 

 It is traversed by the urino- genital canal, through 

 which the urinary and genital products are dis- 

 charged. The dorsal or posterior part of the 

 penis has very vascular walls, and forms the 

 corpus spongiosum ; while the ventral or anterior 

 surface is stiffened by the corpora cavernosa. 

 The free end of the penis is soft, and obliquely 

 truncated ; and is invested by a loose sheath of 

 skin, the prepuce : the external aperture of the 

 urethra is a slit-like opening on its posterior 

 surface. 



g, The uterus masculinus is a large median sac, 



slightly bilobed in front, attached to the dorsal 

 surface of the urino- genital canal, into which it 

 opens, and extending forwards along the dorsal 

 surface of the bladder to about the middle of its 

 length. 



It is formed from the posterior ends of the 

 pronephric ducts, and corresponds to the vagina 

 of the female. 



h. The posterior ends of the vasa deferentia are 

 slightly dilated, and run back, side by side, along 

 the dorsal surface of the neck of the bladder, 

 between it and the uterus masculinus. They 

 open separately into the ventral wall of the uterus 



